Emerging works done in the area of inductive power transfer has been done using ferrite materials to increase the magnetic coupling. Large ferrite cores with a length of 3 meter were used to build transmitting and receiving coils for wireless power transfer. The dipole coils were wound on ferrite cores with piecewise linear shape. Such shape makes the flux distribution inside the ferrite core become uniform in an average sense, and the flux lines between two parallel dipole coils become more concentrated hence the power transfer efficiency is improved. The efficiency data provided by was promising, but the model is not practical for well applications as the diameter of the well can rarely be as large as 3 meters. Some research has studied the potential approach of adding a cement layer to the oil pipe to form an acoustic waveguide so that acoustic power can transfer along oil pipe wirelessly. The role of the cement layer in is to act as a wave propagating media that concentrate the most of acoustic energy inside of it. Though such approach can concentrate the propagating acoustic power and improve the power transfer efficiency, there may be potential problems of impedance matching between the piezoelectric transducers and the cement layer. Also, the propagating wave energy will suffer from serious reflection if there is a gap or fracture on the cement layer.
Improved wireless transfer systems and methods utilizing ferrite materials are discussed herein.